The present invention relates to a lock device for decomposable furniture elements, particularly for wooden-frame chairs, and to a furnishing item incorporating such a device.
In the following description, reference is made purely by way of example to a decomposable wooden-frame chair.
Decomposable wooden-frame chairs are normally assembled by means of a number of joints, each defined by a first and at least a second substantially perpendicular element, and by means for locking the elements together in a releasable manner.
In most cases, the lock means consists of self-threading wood screws screwed through the elements, or of screw-nut lock devices between two or more elements.
Known lock devices comprise a threaded nut connected to a first of the elements, normally by means of adhesive or by fitting it inside a respective seat; and a screw fitted in rotary manner to the second element, having a head cooperating with an axial stop on the second element, and designed to engage the nut screw for mutually connecting the two elements.
Though widely used, known lock devices of the aforementioned type are invariably unreliable as regards long-term performance, especially when used for connecting elements made of wood or similar. In fact, in general, the design characteristics of known devices, and especially the self-threading screws, fail to maintain the initial connection of the elements substantially unchanged alongside variations in the geometric and dimensional characteristics of the elements caused, for example, by aging of the material.